Guide system with suction

ABSTRACT

A guide catheter for use in treating sinuses, the catheter including a catheter shaft configured to provide suction about a balloon catheter and a distal portion shaped for navigating body anatomy. In one embodiment, the guide catheter includes a valve for sealing the balloon catheter and a vent for controlling suction.

This application is a continuation of U.S. patent application Ser. No.15/165,209, entitled “Guide System with Suction,” filed May 26, 2016,published as U.S. Pub. No. 2016/0324535 on Nov. 10, 2016, which is adivisional application of U.S. patent application Ser. No. 12/408,524,entitled “Guide System with Suction,” filed Mar. 20, 2009, nowabandoned.

FIELD OF THE INVENTION

The present invention relates generally to medical devices and methodsand more particularly to devices, systems and methods for treatingsinusitis.

BACKGROUND

Chronic sinusitis is a medical condition that affects the lives ofmillions of people every year. In fact, it has been estimated thatchronic sinusitis results in 18 million to 22 million physician officevisits per year in the United States. Chronic sinusitis refers toinflammation of the paranasal sinuses that lasts for three months ormore or that occurs frequently. The condition can be very debilitating,often causing headaches, facial pain, excessive nasal drainage,difficulty breathing through the nose and other symptoms, and oftenmaking certain activities such as flying in an airplane very painful.The overall costs to society of chronic sinusitis are enormous, in termsof medical costs, missed days of work, etc.

The paranasal sinuses are air spaces behind the bones of the upper face,between the eyes and behind the forehead, nose and cheeks. On each sideof the face there is one set of frontal sinuses (in the forehead),maxillary sinuses (in the cheek bones), ethmoid sinuses (between theeyes) and sphenoid sinuses (farther back behind the eyes). The frontal,maxillary and sphenoid sinuses are all connected to, and drain into, thenasal cavity via openings called ostia (“ostium” singular). The nasalcavity and paranasal sinuses are made of bone covered with mucoustissue, and the mucous tissue has small, hair-like projections calledcilia, which move together to sweep mucus through and out of the sinusesas a kind of filter. When the mucosal tissue of the sinuses becomesinflamed, often due to infection, it sometimes swells and can block oneor more ostia, thus preventing the movement of mucus from the sinuses tothe nasal cavity and thus causing blockage, pressure build-up, and thesymptoms of sinusitis. This blockage can sometimes last for long periodsof time or recur again and again, causing a great deal of discomfort.

One of the ways to treat sinusitis is by restoring the flow of mucusthrough and out of the sinuses via the openings (ostia) into the nasalcavity. Typically, the initial therapy attempted in treating sinusitisis drug therapy and nasal sprays—anti-inflammatory agents to reduceinflammation of the mucosal tissue and antibiotics to treat infection. Alarge number of patients do not respond to nasal spray/drug therapy,however. Patients with chronic or recurring sinusitis may and do notrespond to drug therapy may then decide to undergo a surgical procedure.

One form of surgical procedure for treating chronic sinusitis is acalled Functional Endoscopic Sinus Surgery (“FESS”). In FESS, a rigidendoscope is inserted into the nose, and a surgeon uses one or morerigid instruments, such as shavers and graspers, to remove diseased orhypertrophic mucosal tissue and bone and in some cases enlarge the ostiaof the sinuses to attempt to “open up” and restore normal drainage ofthe sinuses. These FESS procedures are successful in many cases but dohave a number of significant drawbacks. For example, general anesthesiais required for a FESS procedure. Also, because significant amounts ofsoft tissue and bone are typically removed, FESS can cause significantbleeding and post-operative pain, and thus recovery from surgery can bepainful and take many days or even weeks. Because FESS procedures areoften associated with significant postoperative bleeding, nasal packingis frequently placed in the patient's nose for some period of timefollowing the surgery. Such nasal packing can be uncomfortable and caninterfere with normal breathing, eating, drinking etc. This packingoften must be removed and replaced, which can be very uncomfortable.Scar tissue may also have to be removed in the physician's office, in aprocedure called a “debridement,” which can also be very painful. Also,some patients remain symptomatic even after multiple FESS surgeries.Additionally, some FESS procedures are associated with risks ofiatrogenic orbital, intracranial and sinonasal injury. Manyotolaryngologists consider FESS an option only for patients who sufferfrom severe sinus disease (e.g., those showing significant abnormalitiesunder CT scan). Thus, patients with less severe disease may not beconsidered candidates for FESS and may be left with no option but drugtherapy. One of the reasons why FESS procedures can be bloody andpainful relates to the fact that instruments having straight, rigidshafts are used. In order to target deep areas of the anatomy with suchstraight rigid instrumentation, the physician needs to resect and removeor otherwise manipulate any anatomical structures that may lie in thedirect path of the instruments, regardless of whether those anatomicalstructures are part of the pathology.

As an alternative to traditional FESS procedures, the assignee of thepresent application has invented a number of less invasive/lesstraumatic systems, devices and methods for treating chronic sinusitis byexpanding openings between the nasal cavity and the paranasal sinusesusing an expandable dilation device. In some instances, these and othermethods for treating sinusitis or other conditions may involve advancingone or more devices into the nasal cavity and/or a paranasal sinus via aguide device, such as a guide catheter. Because the anatomy of the nasalcavity, the paranasal sinuses and the openings between the two is verycomplex, small and tortuous, and because damage to mucosal tissue in thenasal cavity and sinuses may cause post-operative pain and bleeding, aneed exists for guide devices that are relatively easy to use in thisanatomy and are as atraumatic as possible. The present disclosureaddresses these and other needs.

SUMMARY

Briefly and in general terms, the present disclosure is directed to asystem and method for treating paranasal sinuses. In one particularaspect, the disclosed system and method is employed to treat sinusitis.

In one particular embodiment, the system for treating sinuses includes aguide catheter including a catheter shaft configured to receive aballoon catheter and to provide suction while the balloon catheterresides in the catheter shaft. The guide catheter can further include aproximal portion having a first stiffness and a distal portion having asecond stiffness less than the first stiffness. The distal portion canbe curved and have a diameter which is less than a diameter of theproximal portion. The system can additionally include a valve forsealing the balloon catheter as well as a suction port and vent.

In further embodiments, the system is contemplated to include aguidewire over which the balloon catheter can be advanced. It is alsocontemplated that the guidewire can be illuminating. Moreover, thedistal tip of the guide catheter can be beveled in a manner tofacilitate placement behind an ucinate process and can further embody aflexible material providing a less traumatic interface for engaginganatomy such as an ethmoid bulla. The flexibility of the distal tip canbe chosen such that it expands to receive a balloon catheter.Additionally, the guide catheter can embody a tapered profile such thata distal portion thereof defines a smaller dimension than a proximalsection.

The guide catheter can also include a proximally oriented flangeproviding a connection to other devices. The flange can be equipped withstructure to register with such other devices as well as operatorgripping surfaces. A vent is further contemplated to provide suctioncontrol.

Various different shapes of the distal end of the guide catheter arealso contemplated. In particular, the distal tip can include variousshaped flange structures intended to reduce trauma. The tip can alsoinclude structure providing visualization under fluoroscopy.

In related methods, treatment of the sinuses can include inserting aguide catheter within a head of a patient and advancing a flexibledevice through the guide catheter. A suction force is generated aboutthe flexible device and the flexible device is advanced beyond a distalend of the guide catheter and into the patient's sinuses. In oneparticular aspect, the flexible device is a balloon catheter and theballoon catheter is employed to dilate an ostium of a paranasal sinus.The method can further involve employing a guidewire over which theinterventional devices are placed.

Further aspects, details and embodiments of the present disclosure areset forth in the following detailed description of the invention and theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of a system for catheter-basedminimally invasive sinus surgery of the present invention being used toperform a sinus surgery procedure on a human patient.

FIG. 1A is an enlarged view of portion “1A” of FIG. 1.

FIGS. 2A through 2D are partial sagittal sectional views through a humanhead showing various steps of a method for gaining access to a paranasalsinus using a guide and thereafter dilating or remodeling the ostialopening into a sphenoid paranasal sinus.

FIGS. 3A through 3D are coronal sectional views through a human headshowing various steps of a method for gaining access to a paranasalsinus using a guide and thereafter dilating or remodeling the ostialopening into a maxillary paranasal sinus.

FIGS. 4A through 4D are partial coronal sectional views through a humanhead showing various steps of a method of accessing a maxillaryparanasal sinus through an artificially created opening of the paranasalsinus and then dilating the artificially created opening, the naturalparanasal sinus ostium or both.

FIG. 5A shows a perspective view of a tubular guide equipped foroptional suctioning.

FIG. 5B shows a side view of an alternative embodiment of a tubularguide with a pinch tube.

FIG. 6 depicts a partial cross-sectional view of a guide catheter systemincluding a balloon catheter and suction structure.

FIG. 7 shows a distal portion of the guide catheter system depicted inFIG. 6.

FIGS. 8 through 11 depict treating a sinus cavity with a guide cathetersystem.

FIG. 12 shows an alternative distal portion for a guide catheter.

FIG. 13 depicts a cross-section of a distal terminal end portion of aguide catheter system.

FIGS. 14A through 14C shows various views of a distal terminal endportion of a guide catheter system.

FIGS. 15A and 15B show a distal terminal end portion of an alternativeguide catheter system.

FIG. 16 shows another alternative terminal end portion of a guidecatheter.

FIGS. 17A and 17B depict another approach to a terminal end portion.

FIGS. 18A and 18B show a further approach to a terminal end.

FIGS. 19A through 19D depict yet further terminal end portions for aguide catheter system.

FIGS. 20A and 20B show views of an additional approach to a distal endportion of a guide catheter.

FIGS. 21A through 21C depict various views of a terminal end portion forguide catheter system which include an angled surface.

FIGS. 22A and 22B show another guide catheter system with an ovalterminal end opening.

FIG. 23 depicts another alternative terminal end portion of a guidecatheter system.

FIGS. 24A-1 through 24C depict various configurations for a sealingstructure for a guide catheter.

FIGS. 25A and 25B are partial cross-sectional views depictingalternative approaches to a hub assembly for a guide catheter.

FIG. 26 depicts a guide catheter hub including a suction connection.

FIGS. 27A and 27B show a partial cross-sectional view of an auxiliarydevice connecting with a guide catheter hub.

DETAILED DESCRIPTION

The following detailed description, the accompanying drawings and theabove-set-forth Brief Description of the Drawings are intended todescribe some, but not necessarily all, examples or embodiments of theinvention. The contents of this detailed description do not limit thescope of the invention set forth in the claims.

A number of the drawings in this patent application show anatomicalstructures of the ear, nose and throat. In general, these anatomicalstructures are labeled with the following reference letters:

Nasal Cavity NC Nasopharynx NP Frontal Sinus FS Sphenoid Sinus SSSphenoid Sinus Ostium SSO Maxillary Sinus MS

FIGS. 1 and 1A illustrate a patient on an operating table with aminimally invasive surgery system in position to perform a dilationprocedure on one or more paranasal sinuses. The system shown includes aC-arm fluoroscope 1000, a first introducing device 1002 (e.g., a guidecatheter or guide tube), a second introducing device 1004 (e.g., aguidewire or elongate probe) and a working device 1006 (e.g., a ballooncatheter, other dilation catheter, debrider, cutter, etc.).

In some embodiments, the devices 1002, 1004, 1006 may be radiopaqueand/or may incorporate radiopaque markers such that C-arm fluoroscope1000 may be used to image and monitor the positioning of the devices1002, 1004, 1006 during the procedure. In addition to, or as analternative to, the use of radiographic imaging, the devices 1002, 1004,1006 may incorporate and/or may be used in conjunction with one or moreendoscopic devices, such as the typical rigid or flexible endoscopes orstereo endocscopes used by otolaryngologists during FESS procedures.Also, in addition to or as an alternative to radiographic imaging and/orendoscopic visualizations, some embodiments of the devices 1002, 1004,1006 may incorporate sensors which enable the devices 1002, 1004, 1006to be used in conjunction with image guided surgery systems or otherelectro-anatomical mapping/guidance systems including but not limitedto: VectorVision (BrainLAB AG); HipNav (CASurgica); CBYON Suite (CBYON);InstaTrak, FluoroTrak, ENTrak (GE Medical); StealthStation Treon, iOn(Medtronic); Medivision; Navitrack (Orthosoft); OTS (Radionics); VISLAN(Siemens); Stryker Navigation System (Stryker Leibinger); Voyager, Z-Box(Z-Kat Inc.) and NOGA and CARTO systems (Johnson & Johnson).Commercially available interventional navigation systems can also beused in conjunction with the devices and methods. Furthernon-fluoroscopic interventional imaging technologies including but notlimited to: OrthoPilot (B. Braun Aesculap); PoleStar (Odin MedicalTechnologies; marketed by Medtronic); SonoDoppler, SonoWand (MISON); CTGuide, US Guide (UltraGuide) etc. may also be used in conjunction withthe devices and methods. Guidance under magnetic resonance is alsofeasible if the catheter is modified to interact with the systemappropriately.

The devices and methods of the present invention relate to the accessingand dilation or modification of sinus ostia or other passageways withinthe ear nose and throat. These devices and methods may be used alone ormay be used in conjunction with other surgical or non-surgicaltreatments, including but not limited to the delivery or implantation ofdevices and drugs or other substances as described in copending U.S.Patent Application Ser. No. 10/912,578 entitled Implantable Devices andMethods for Delivering Drugs and Other Substances to Treat Sinusitis andOther Disorders filed on Aug. 4, 2004, the entire disclosure of which isexpressly incorporated herein by reference.

FIGS. 2A-2D are partial sagittal sectional views through a human headshowing various steps of a method of gaining access to and treating aparanasal sinus using a guide catheter. Although FIGS. 2A-2D demonstratea method for accessing and treating a sphenoid paranasal sinus, inalternative embodiments this or analogous methods and devices may beused to access and treat any of the other paranasal sinuses (maxillary,frontal and/or ethmoid).

In FIG. 2A, a first introducing device in the form of a guide catheter200 is introduced through a nostril and through a nasal cavity NC to alocation close to an ostium SSO of a sphenoid sinus SS. The guidecatheter 200 may be flexible. Flexible devices are defined as deviceswith a flexural stiffness less than about 200 pound-force per inch overa device length of one inch. The guide catheter 200 may be straight orit may incorporate one or more preformed curves or bends. In embodimentswhere the guide catheter 200 is curved or bent, the deflection angle ofthe curve or bend may be in the range of up to 135°. Examples ofspecific deflection angles formed by the curved or bent regions of theguide catheter 200 are 0°, 30°, 45°, 60°, 70°, 90°, 120° and 135°. Guidecatheter 200 can be constructed from suitable elements like PEBAX,Polyimide, Braided Polyimide, Polyurethane, Nylon, PVC, Hytrel, HDPE,PEEK, metals like stainless steel and fluoropolymers like PTFE, PFA, FEPand EPTFE. Guide catheter 200 can have a variety of surface coatingse.g. hydrophilic lubricious coatings, hydrophobic lubricious coatings,abrasion resisting coatings, puncture resisting coatings, electricallyor thermal conductive coatings, radiopaque coatings, echogenic coatings,thrombogenicity reducing coatings and coatings that release drugs.

In FIG. 2B, a second introduction device comprising a guidewire 202 isintroduced through the first introduction device (i.e., the guidecatheter 200) so that the guidewire 202 enters the sphenoid sinus SSthrough the ostium SSO. Guidewire 202 may be constructed and coated asis common in the art of cardiology.

In FIG. 2C, a working device 204, for example a balloon catheter, isintroduced over guidewire 202 into the sphenoid sinus SS. Thereafter, inFIG. 2D, the working device 204 is used to perform a diagnostic ortherapeutic procedure. In this particular example, the procedure isdilation of the sphenoid sinus ostium SSO, as is evident from FIG. 2D.However, the present invention may also be used to dilate or modify anyother sinus ostium or other man-made or naturally occurring anatomicalopening or passageway within the nose, paranasal sinuses, nasopharynx oradjacent areas, including but not limited to natural paranasal sinusostia of the maxillary, frontal and/or ethmoid sinuses. After thecompletion of the procedure, guide catheter 200, guidewire 202 andworking device 204 are withdrawn and removed. In this or any of theprocedures described in this patent application, the operator mayadditionally advance other types of catheters or of the presentinvention, a guidewire 202 may be steerable (e.g. torquable, activelydeformable) or shapeable or malleable. Guidewire 202 may comprise anembedded endoscope or other navigation or imaging modalities includingbut not limited to fluoroscopic, X-ray radiographic, ultrasonic,radiofrequency localization, electromagnetic, magnetic, robotic andother radiative energy based modalities. In this regard, some of thefigures show optional scopes SC is dotted lines. Such optional scopes SCmay comprise any suitable types of rigid or flexible endoscopes and suchoptional scopes SC may be separate from or incorporated into the workingdevices and/or introduction devices of the present invention.

Optionally, the methods disclosed herein may also comprise the step ofcleaning or lavaging anatomy within the nose, paranasal sinus,nasopharynx or nearby structures including but not limited to irrigatingand suctioning. The step of cleaning the target anatomy can be performedbefore or after a diagnostic or therapeutic procedure.

The methods of the present invention may also include one or morepreparatory steps for preparing the nose, paranasal sinus, nasopharynxor nearby structures for the procedure, such as spraying or lavagingwith a vasoconstricting agent (e.g., 0.025-0.5% phenylephyrine orOxymetazoline hydrochloride (Neosynephrine or Afrin) to cause shrinkageof the nasal tissues, an antibacterial agent (e.g., provodine iodine(Betadine), etc. to cleanse the tissues, etc.

As shown in FIGS. 3A-3D, in one embodiment a maxillary sinus may betreated by dilating an ostium thereto. As shown in FIG. 3A, a guidecatheter 290 may be advanced into a patient's nostril to position adistal end thereof adjacent the maxillary sinus ostium. As shown in FIG.3B, a guidewire 294 may then be advanced through the guide 290 andthrough the maxillary sinus ostium, into the maxillary sinus. Next, asshown in FIG. 3C, a balloon catheter 302 may be advanced through theguide catheter 290 over the guidewire 294, to position an expandableballoon 304 of the balloon catheter 302 within the maxillary ostium.Then, as shown in FIG. 3D, the expandable balloon 304 may be inflated todilate the natural paranasal sinus ostium of the maxillary sinus. Whenthe dilation procedure is complete, the guide catheter 290, guidewire294 and balloon catheter 302 may all be removed from the patient. In analternative embodiment, the guide catheter 290 and/or the guidewire 294may be left in the patient, the balloon catheter 302 may be removed, andanother flexible device (not shown in the figures) may be advanced overand/or through the guide catheter and/the guidewire 294 into themaxillary sinus to perform an additional procedure. For example, in oneembodiment, an irrigation catheter may be advanced through the guidecatheter 290 and used to irrigate the sinus. Such an irrigation cathetermay be advanced without a guidewire 294 or using a guidewire 294 inalternative embodiments.

FIGS. 4A-4D are partial coronal sectional views through a human headshowing various steps of a method of accessing a maxillary paranasalsinus through an artificially created opening into the sinus anddilating the artificial opening, the natural paranasal sinus ostium orboth. In some embodiments, rather than accessing a paranasal sinus viathe natural sinus ostium, an artificial opening may be made into asinus. In some embodiments, a guide may be used to then guide a ballooncatheter or other dilator (with or without guidewire) through theartificial opening, into the sinus. The dilator may then be advanced tothe natural paranasal sinus ostium and used to dilate the naturalostium, may be used to dilate the artificial opening, or both.

In FIG. 4A, a puncturing device 300 is inserted through a nostril andused to create an artificial opening in a maxillary sinus. Examples ofsuch puncturing devices include but are not limited to straight needles,needles with bent shafts, dissectors, punches, drills, corers, scalpels,burs, scissors, forceps and cutters. In FIG. 4B, puncturing device 300is withdrawn and a working device, for example a balloon catheter 302,is introduced through the artificial opening into the maxillary sinus.In FIG. 4C, balloon catheter 302 is used to dilate the artificiallycreated opening in the maxillary sinus. After this step, the ballooncatheter 302 is withdrawn. In another embodiment, as shown in FIG. 4D,the balloon catheter 302 may be advanced through the artificial openinginto the maxillary sinus and then advanced farther into the maxillarysinus to position the balloon of the catheter 302 in the naturalparanasal sinus ostium. In some embodiments, this advancement to thenatural ostium may be performed after dilating the artificial opening.Alternatively, the balloon catheter 302 may be advanced in someembodiments without dilating the artificial opening.

In some embodiments, a balloon catheter 302 may be advanced over aguidewire to the natural paranasal sinus ostium. Alternatively, theballoon catheter 302 may be advanced without the use of a guidewire inother embodiments. In some embodiments, the puncturing device 300 mayhave a lumen through which an introduction device (e.g., a guidewire orother elongate probe or member), may be inserted into the maxillarysinus, and the puncturing device 300 may then be removed, leaving suchintroduction device (e.g., a guidewire or other elongate probe ormember) in place. In such cases, the working device (e.g., ballooncatheter 302) may incorporate a lumen or other structure that allows theworking device (e.g., balloon catheter 300) to be advanced over thepreviously inserted introduction device (e.g., a guidewire or otherelongate probe or member). In some embodiments, the piercing device mayinclude a lumen, and the balloon catheter 302 may be advanced throughthe piercing device into the maxillary sinus, either with or without aguidewire in various embodiments. Again, similar methods and devices maybe used to access and treat other paranasal sinuses in alternativeembodiments.

In another alternative embodiment (not shown in FIGS. 4A-4D), a piercingdevice may be used to create an opening into a maxillary sinus at adifferent location, and a guide catheter may be used to access the sinusthrough the opening. For example, in one embodiment the artificialopening may be made through a canine fossa into a maxillary sinus. Inanother embodiment, a trephine incision may be made into a frontalparanasal sinus. In other embodiments, an artificial opening may beformed into an ethmoid or sphenoid sinus. In some embodiments, a guidemay then be placed through the artificial opening and used to access thenatural paranasal sinus ostium. In other embodiments, the guide cathetermay remain outside the sinus, near the artificial opening, and used toguide a guidewire and/or other device(s) into the sinus. In alternativeembodiments, the artificial opening may be dilated, the naturalparanasal sinus ostium may be dilated, or both. These methods may beapplied to any paranasal sinus. As will be described in greater detailbelow, any of these guide catheters, whether used to access a paranasalsinus via a natural or artificial opening, may be provided with suctioncapabilities according to various embodiments of the present invention.

Any of the guide catheters or other luminal devices disclosed herein mayhave suction capabilities and thus can comprise an arrangement forsuctioning an anatomical region through the distal end of the guidecatheter or device. In some embodiments, a guide catheter may beprovided along with an adapter to attach the guide to a suction source.In another embodiment, a guide catheter may have an integrated orbuilt-in suction attachment, so that an adapter is not necessary.Currently, physicians use a traditional suction device to clear thesurgical field when using surgical devices in the nasal cavity andparanasal sinuses. This requires the surgeon to frequently exchangedevices, picking up and putting down the traditional suction device manytimes per case. Allowing the surgeon to suction through the guidecatheter while simultaneously passing guidewires, balloons, irrigationcatheters and/or the like through the guide catheter can simplify thesurgical procedure. A suction adapter can attach to a proximal end ofthe guide catheter. It can include a valve in-line with an axis of theguide catheter shaft, the valve allowing devices such as guidewires,balloons, and irrigation catheters to be passed through the suctionadapter and guide catheter while maintaining suction through the lumenof the guide catheter. Extension tubing can be configured to run offsetfrom the body of the suction adapter. The extension tubing may terminatein a stepped adapter and/or an on-off valve to improve ease of use.

To connect to the guide catheter, a male slip-fit luer can be used. Thisprovides a mechanically secure and airtight seal while allowing for easyrotational adjustment of the guide catheter with respect to the suctionadapter. Moreover, a hole through the body of the suction adapter allowsfor easy control of the amount of suction through the guide catheter.When the hole is not occluded, there is little or no vacuum at thedistal end of the guide catheter. The surgeon can partially or fullyocclude the hole with his finger to increase the vacuum at the tip ofthe guide catheter. An on/off switch can be further provided to controlsuction activation. The switch is placed to “on” and then the hole isoccluded to initiate suctioning. Further, a silicone or polyisoprrenevalve can be used to maintain a seal around guidewires, balloons orirrigation catheters. The valve is fully closed when no device ispresent. Extension tubing in the form of lightweight tubing can be usedto connect the suction adapter to heavier gauge tubing used commonly inoperating rooms. The tubing has sufficient wall thickness to preventcollapse under vacuum but does not add mass or ergonomic challenges tothe guide catheter.

For example, FIG. 5A shows a guide with a proximal adapter for attachingto suction. More specifically, the guide catheter 500 can comprise anelongate tube 502 that may be made of suitable biocompatible materials,including but not limited to metals such as stainless steel, titanium,Nickel-titanium alloy (e.g., Nitinol), etc.; plastics such as PEBAX,PEEK, Nylon, polyethylene, etc. The distal region of elongate tube 502may comprise a curved, bent or angled region. In some embodiments, thedistal end of elongate tube 502 may comprise an atraumatic tip 504.Although various modes of construction may be used, in the exampleshown, an elongate hypotube 506 is disposed on the outer surface ofelongate tube 502 and the proximal end of guide catheter 500 comprises abranched or Y-connector 508. The proximal region of Y-connector 508comprises a straight arm 510 and a side arm 512. The proximal end ofstraight arm 510 comprises a suitable hub 514. In one embodiment, hub514 is a female luer hub. In another embodiment, hub 514 comprises arotating hemostasis valve such as a Touhy-Borst adapter. The proximalend of side arm 512 comprises a suitable hub 516. In one embodiment, hub516 comprises a rotating hemostasis valve such as a Touhy-Borst adapterto adjust the amount of suction. Hub 516 is connected to a suction tube518 that provides suction to guide catheter 500. Thus, guide catheter500 can be used to provide suction as well as introduce one or morediagnostic, therapeutic or access devices into the anatomy.

In an alternative approach, the guide catheter can be further equippedwith a pinch tube 550 (See FIG. 5B). The pinch tube is connected to aproximal end of the Y-connecter 508 and can be formed from silicone oranother flexible material. Further, a proximal end of the elongate tube502 can be configured with a female luer 552 which mates with a maleluer 554 attached to the Y-connector 508. In use, the pinch tube 550 ispinched closed by a physician about a guidewire 551 or other device toocclude the lumen extending through the guide to thereby facilitatesuctioning. As before, suction forces are applied through the side arm512.

Turning now to FIGS. 6 and 7, in one embodiment, a guide catheter system600 may include a guide catheter 601 having a shaft 610 and a hubassembly 604 disposed at the proximal end of the shaft 610. The shaft610 may include a proximal portion 603 having a first diameter, aterminal end portion 602 having a second, smaller diameter, a taperingtransition 614 between the two, and a lumen 608 extending through thelength of the shaft 610 and through the hub assembly 604. (The internalportion of the hub assembly 604 may be a lumen, a chamber or the like influid communication with the lumen 608 of the catheter shaft 610.) Insome embodiments, the guide catheter system 600 may further include aguidewire 612 and/or a balloon catheter 606, as shown in FIG. 6. In someembodiments, the guide catheter system 600 may further include a suctiondevice, such as suction tubing 633.

The outer profile of the shaft 610 is configured for advancement into anasal cavity so that one or more devices may be advanced through thelumen 608 into a paranasal sinus. The tapering transition 614 isprovided between the shaft proximal portion 603 and the distal portion602 such that the distal portion 602 has a smaller cross-section thanthe proximal portion 603. In this way, a balloon catheter 606 can residein the proximal portion 603 while suction forces are passed through thelumen 608, around the balloon catheter 606 structure. This configurationmay be useful, for example, in advancing the guide catheter system 600into a nostril of a patient with the balloon catheter 606 preloaded intothe guide lumen 608 and allowing for suction during advancement andpositioning of the guide catheter 601. Suction during advancement andpositioning of the guide catheter 601 is advantageous because it allowsfor the removal of blood and mucus from the field in which the surgeonis working, thus facilitating visualization of the area and access to aparanasal sinus.

The shaft distal terminal portion 602 of the guide catheter 601 definesa specific curved profile intended to direct one or more devicesadvanced through the lumen 608 into a natural or manmade opening of aparanasal sinus. In one embodiment, the most distal tip 616 of theterminal end portion 602 is more flexible than the rest of the shaft610. Accordingly, PEBAX is one contemplated material for the distal tip616. An intermediate portion 618 of the shaft 610, which may include thetapering transition 614, may be made of a flexible material as well, butin one embodiment this material may be less flexible than material usedto form the distal tip 616. For example, in one embodiment, theintermediate portion 618 may be formed of a nylon material. The proximalportion 603 of the shaft 610 proximal to this intermediate portion 618may be formed of a more rigid material, such as but not limited to amore rigid polymer and/or a stainless steel hypotube 619.

One advantage of the flexible distal tip 616 is that it causes lesstrauma to soft mucosal tissue lining the nasal cavity as the guidecatheter 601 is advanced, manipulated and retracted. For example, whenthe guide catheter 601 is advanced into the nasal cavity, the tip 616may often contact the ethmoid bulla, and a flexible tip 616 will causeless trauma than a rigid one. In some embodiments, the distal tip 616may also expand as a deflated balloon catheter 606 is drawn back intothe guide catheter after a balloon dilation procedure has beenperformed. This expansion (or “give”) may reduce the amount of forcerequired to pull the balloon catheter 606 back into the guide catheter601 after a procedure, thus making use of the balloon catheter 606/guidecatheter 601 system easier. This also allows the distal tip 616 diameterto be made smaller than it otherwise would, which further reduces traumaduring use and also facilitates positioning of the distal tip 616 at adesired location in the anatomy. The tip 616 may also be provided withan expandable radiopaque band to aid in tracking positioning during aninterventional procedure as well as to maintain an atraumatic profile.

Further, the PEBAX distal tip 616 is shaped relative to the adjacentproximal portion 618 for navigation through and about nasal cavitystructures. For instance, in one embodiment, the curved shape of the tipportion 616 facilitates navigating about an ucinate process, so that oneor more devices may be navigated into a maxillary sinus. In oneembodiment, a junction between the distal tip 616 and the adjacentintermediate portion 618 is slanted. This slanted connection increasesthe area of the distal tip 616 portion relative to the intermediateportion 618, thus increasing the area of the most flexible portion ofthe shaft 610, which enhances the prevention of soft tissue trauma. Theangled shape of the terminal end portion 602 is retained in part due tothe more rigid nylon of the intermediate portion 618 and its slantedjunction with the distal tip portion 616.

In various alternative embodiments, a guide device such as the onedescribed above and below may have any suitable angled configuration.For example, embodiments may be provided with different angles tofacilitate access to maxillary, frontal, sphenoid and ethmoid paranasalsinuses. In various embodiments, the distal tip 616 may be angledrelative to the rest of the shaft 610 at angles from approximately 0° toapproximately 180°. In some embodiments, a combination of guidecatheters 601 having different angled configurations may be provided,such as a set of guide catheters 601 having angles of 0°, 30°, 70° and110°. A surgeon may then select a guide catheter 601 with a desiredangle for accessing a given paranasal sinus. In various embodiments, anyangle or guides with any combination of angles may be provided.

In various embodiments, the outer an inner diameters of the shaft 610,including the terminal end portion 602, tapering transition 614 andproximal portion 603, may have a number of different sizes, as long asthe shaft 610 is configured for advancement into the nasal cavity. Theterminal end portion 602 and distal tip portion 616, in particular, maybe sized to facilitate positioning near an opening to a paranasal sinus.In one embodiment, for example, the distal tip 616 can have an innerdiameter of approximately 0.093 inches. This diameter structure canextend longitudinally from the tip 616 and to the catheter portiondistal to the taper 614 and can define a relatively long dimension. Atip envelop 620 of the terminal end portion 602, however, can assume arelatively short dimension so that it can more easily pass through nasalanatomy and thus potentially engaging less structure as it is inserted,for example, past a middle turbinate. The “tip envelope,” for thepurposes of this application, is defined as the length of a line drawnperpendicularly from the extreme distal end of the distal tip 616 to anoppositely facing surface of the straight portion of the terminal endportion 602, as shown in FIG. 7.

As shown in FIGS. 6 and 7, in one embodiment, the extreme distal end ofthe distal tip 616 may have a bevelled shaped. The bevelled shape alsofacilitates insertion and positioning relative to nasal cavity anatomy,such as directing the guide catheter 601 around the ucinate process togain access to the maxillary sinus ostium. Moreover, the particularconfiguration of the beveled tip 616 permits an operator to view theopening of the tip when the device is placed within a nostril. This isdue to the opening of the bevelled structure pointing back toward theoperator. Such direct viewing of the opening of the tip 616 can aid indevice manipulation and positioning.

In some embodiments, the lumen 608 in the terminal end portion 602 mayhave an inner diameter sized so that when the balloon catheter 606 isadvanced within that portion of the lumen 608, suction is no longerpossible, since an interference fit is created between the inner wall ofthe lumen 608 of the distal terminal end portion 602 and the outersurface of the balloon. In an alternative embodiment, it may still bepossible to draw suction through the lumen 608 and around the ballooncatheter 606, even in this advanced position, though the amount ofsuction force will be less when the balloon resides in the terminal endportion 602 compared with when it resides in the proximal shaft portion603. Suction force may then be resumed again when the balloon catheter606 is advanced distally beyond the tip 612 to perform an interventionalprocedure, although in some cases the primary use of suction may beduring initial advancement and positioning of the guide catheter system600 in the nasal cavity.

A proximal valve 624 is provided within the guide lumen 608 (or chamberof the hub 604). In one embodiment, the valve 624 forms a seal about theballoon catheter 606 to thereby facilitate the application of suctionforces within the lumen 608. In one embodiment, the valve can beconfigured so that it also may form a seal around a guidewire 612.However, in an alternative embodiment, the valve does not form a sealabout a guidewire 612, so that suction is only created when the ballooncatheter 606 or another flexible device having a larger diameter thanthe guidewire 612 is positioned within the lumen 608.

The hub 604 of the guide catheter 601 further includes a vent 628 and asuction port 630. A most proximal portion is equipped with a flange 631shaped for easy gripping by an operator. In one embodiment, for example,the flange 631 may be used by a surgeon to grip the guide catheter 601like a syringe and advance the balloon catheter 606 through the guidecatheter 601 with the same hand. In alternative embodiments, eitherstandard or custom suction tubing 632 can be attached to the suctionport 630 to create the desired suction force. Moreover, the suction port630 is angled proximally so that a guidewire 612 advanced through thehub 604 will not exit the suction port 630.

The vent 628 is sized and positioned to accept an operator's finger, sothat suction provided through the suction port 630 will be applied atthe distal tip 616 of the guide catheter 601. In some embodiments, thevent 628 can define a short tubular path from an outer surface of thehub 604 to an inner wall of the hub 604 and can be directed proximallyin a manner similar to the suction port 630, to prevent a guidewire 612from passing through the vent 628. In one alternative embodiment, thevent 628 may also or alternatively be covered with a grate-likestructure to prevent a guidewire 612 from passing therethrough.

With reference now to FIGS. 8-11, a method of using the guide cathetersystem 600 is described. Although FIGS. 8-11 show use of the guidecatheter system 600 in accessing and treating a frontal paranasal sinus,this or other embodiments may be used to access and treat any of theother paranasal sinuses, including maxillary, sphenoid and ethmoidparanasal sinuses.

Referring to FIG. 8, in one embodiment of the method, a guide catheter601 is first advanced into a nasal cavity and positioned so that theterminal end portion 602 of the guide catheter 601 is located at or nearan opening into a paranasal sinus. In the example shown in FIG. 8, theterminal end portion 602 is positioned near the frontal recess, which isa pathway leading to the frontal sinus ostium (the natural opening intothe frontal sinus). The guide catheter 601 may be positioned in adesired location using an endoscope for visualization and/orfluoroscopy, however, in most cases an endoscope alone will suffice. Insome embodiments, the guide catheter 601 is advanced into the nasalcavity with a guidewire 612 and/or a balloon catheter 606 preloaded intothe guide catheter lumen 608. During advancement and/or positioning ofthe guide catheter 601, suction may be applied by applying suction forcethrough a suction tube coupled with the hub apparatus 604 and by placinga thumb or other finger over the vent 628 to remove blood, mucus and/orother fluids from the area of the terminal end portion This use ofsuction will typically enhance a surgeon's ability to visualize thenasal cavity using an endoscope and thus facilitate location of a targetparanasal sinus ostium.

Still referring to FIG. 8, once the guide catheter 601 is positioned ina desired location in the nasal cavity, the surgeon then advances theguidewire 612 out of the distal opening of the catheter 601 and throughthe natural ostium 650 of a paranasal sinus into the sinus cavity 652.In some embodiments, the guidewire 612 may be an illuminating guidewire.Such an illuminating guidewire may be used to create a transilluminationspot on an external surface of the patient during and/or afteradvancement of the guidewire 612 to confirm that the distal end of theguidewire 612 has entered and resides in the desired paranasal sinus.(See, for example, U.S. patent application Ser. Nos. 11/522,497 and11/803,695, the full disclosures of which are hereby incorporated byreference.) In other embodiments, a non-illuminating guidewire 612 maybe used. In either the illuminating or non-illuminating guidewireembodiment, fluoroscopy may be used to visualize the guidewire 612 inthe paranasal sinus for further confirmation of its location.

Next, as shown in FIG. 9, the balloon catheter 606 is advanced over theguidewire 612 and is positioned and then expanded within the paranasalsinus ostium 650. (In the case of the frontal sinus, as in theseFigures, the balloon of the balloon catheter 606 may be positioned andinflated within the ostium, the frontal outflow tract or both.) Aninflation device (not shown) is provided to inflate the balloon.Thereafter, the balloon catheter is deflated and withdrawn within thedistal terminal end portion 602. In one embodiment, rather thanimmediately withdrawing the balloon catheter 606, instead the balloonmay be repositioned and inflated again to further expand the ostium,expand a portion of the frontal sinus outflow tract and/or the like.Optionally, the balloon catheter 606 may be further withdrawn into theguide catheter 601, and a suction force may be applied to removesubstances from the paranasal sinus cavity or outflow tract or from thenasal cavity.

With reference now to FIG. 10, in an optional step, in some embodiments,the balloon catheter 606 may be removed from the patient via the guidecatheter, and a flexible irrigation catheter 654 may then be passedthrough the guide catheter 601 (either over the guidewire 612 or withouta guidewire, in alternative embodiments), into the paranasal sinus.Irrigation fluid 652, such as saline solution, may then be passed out ofthe irrigation catheter 654 to flush or irrigate the sinus. In someembodiments, the irrigation fluid 652 may simply be allowed to flow outof the sinus without applying suction force. In other embodiments,suction may be applied via the suction guide catheter 601 to assist inremoval of the fluid 652.

At the end of a procedure, as in FIG. 11, the guide catheter 601 and anyremaining devices are removed from the patient. The ostium 650 is leftin a dilated state, which ideally will facilitate normal drainage of thesinus and help treat the patient's sinusitis.

As shown in FIG. 12, an alternate approach to a guide catheter 700 mayinclude a distal terminal end portion 702 which includes multiple turnsor bends. A first bend 704 can be positioned distally with respect to asecond bend 706, where the first bend 704 defines a smaller angle thanthe second bend 706. This “double-bend” configuration may facilitateinsertion of the guide catheter 700 into a nostril in a tip-downorientation and then allow the catheter 700 to be rotated to positionits distal tip 716 at or near a maxillary sinus ostium.

In other alternative embodiments, the terminal end portion 702 of aguide catheter 700 may be configured to facilitate other processes ormanipulations within the nasal cavity. For example, in one embodimentthe terminal end portion 702 may be configured to facilitate pushing anucinate process (or other anatomy) out of the way during aninterventional procedure while a distal tip 716 is positioned as desiredrelative to the treatment site. The “double-bend” approach shown in FIG.12 may help lower insertion and retraction forces required to advanceand retract a balloon catheter through the guide 700. For example,double bends of fifty and sixty degrees can be subjected to less suchforces than a single bend of one hundred ten degrees.

Turning now to FIGS. 13-23, a number of alternative embodiments ofdistal end configurations for guide catheters are shown. Each embodimentmay have advantages in facilitating advancement and/or positioning of aguide catheter within a nasal cavity and/or advancement or retraction ofa balloon catheter or other device(s) into and out of the guidecatheter's distal end. As shown in FIG. 13, in one embodiment, aterminal end tip 750 of a guide catheter may embody an eye-shapedextrusion or molding 752, including a round inner diameter 754.Integrated wings 756 are provided to help gain access to and traversenasal cavity anatomy. For example, the wings 756 may facilitatepositioning the distal end of the guide catheter behind an uncinateprocess to access a maxillary sinus ostium. The wings 756 may allow asurgeon to tease the uncinate anteriorly, thus exposing an open pathwayfor guide access to the maxillary sinus ostium.

Some of the guide catheter distal ends in FIGS. 13-23 also include anoval cross-section. This oval shape may help to minimize the dimensionof he guide in the orientation of anatomic restriction. Because theuncinate process can often be tight against the ethmoid bulla (in ananterior-posterior direction), the guide is ovalized such that thesmaller dimension is oriented between the uncinate and the ethmoidbulla. Various embodiments may include such an oval cross-section withor without wings 756. The soft distal tip material of some embodimentsof the guide catheters allow the cross-sectional shape of the guide tipto change relative to the forces it encounters. Therefore, a soft tipwith a round cross-sectional shape may ovalize while it is being placedbehind the uncinate, thereby reducing the force required to achieve adesired position.

In other approaches, distal terminal end portions of a guide cathetercan include flanged wings of various configurations. Wings can bepositioned at the top, midline or bottom of a tip and the wing can beshort, long, flat or curved. Also, the wings can be flared to form asingle price of material and can be made of any suitable flexible ornon-flexible material in various embodiments, such as but not limited toany number of metals or polymers, such as aluminum foil, stainlesssteel, hard plastic or soft plastic. In one specific approach (FIGS.14A-14C), a distal terminal end portion 750 of a guide catheter caninclude wings 756 formed by aluminium foil. Such wings are againintended to facilitate navigation through sinus anatomy such as for thepurpose of slipping behind an ucinate process. Similarly configuredwings formed from PEBAX are shown in FIGS. 15A and 15B. Yet anotherapproach to facilitating navigation is shown in FIG. 16 which depicts ahard plastic covering 758 formed about a portion the distal terminal end750 of a guide catheter.

Moreover, as shown in FIGS. 17A-17B, navigating wings 757 can also beformed of a stainless steel bar configured across the terminal endgenerally perpendicular to a distal opening formed therein. Anotherapproach to a PEBAX wing structure 756 is shown in FIGS. 18A and 18B.Yet further different approaches are depicted in FIGS. 19A-19D, 20A-20B,21A-21C, 22A-22B and 23, respectively. Of particular note are the angledtip approach with underside wings 756 shown in FIG. 19A and the anglecut tips of FIGS. 21A-21C. Various shaped openings at the terminal endsof the guides are also contemplated such as those depicted in FIGS.21A-21C, 22A-22B and 23.

As shown in FIGS. 24A-24C, various different approaches to a valve 624for sealing a balloon catheter 606 within a guide catheter system arecontemplated. In a first approach, a flat circular gasket 800 with acenter sealing through hole 802 (FIG. 24A). Alternatively, a valve 810defined by a through hole with a double taper 812 can be employed withina guide catheter system. Further, as shown in FIG. 24C, the valve 624can embody a one-way valve 820 with internal flap structure 822.

Turning now to FIGS. 25A and 25B, there are shown alternative approachesto a hub assembly 604 of a guide catheter system 600. By splitting thehub into first 830 and second 840 parts, an improved approach toattaching a valve seal 624 to a catheter shaft 610 is contemplated. In afirst approach, the valve 624 is affixed to the shaft 610 and the twoparts are positioned within the second part of the hub 604. The firstpart of the hub 830 is then inserted in the second part to complete thehub assembly. In an alternate approach (FIG. 25B), the valve 624 iscaptured in the second part 840 of the hub assembly and the end of thecatheter shaft 610. The first part 830 of the hub is configured withflanges 842 which traps the valve 624 in place. Such approaches areintended for ease of assembly.

As shown in FIG. 26, the hub assembly 604 can further include a suctionport 630 including barbs 850. The attachment for a suction tube must beone that allows for ease of attaching and removal, yet also from a tightseal to provide sufficient suction rates with little to no leakage. Thebarbs 850 facilitate such a desirable connection and also define aprofile which does not interfere with an operator during use whether thesuction feature is being employed or not.

Additionally, as shown in FIGS. 27A and 27B, the hub assembly 604 caninclude a proximal opening 860 which can be provided for connecting thehub 604 to other devices. A ridge 862 can be formed within the opening860 and can be sized and shaped to lockingly engage within a cut-outformed on an end of an auxiliary device 866. In this way, an audibleclick can be created by the engagement of the ridge 862 to therebyconfirm a proper register of the hub 604 with auxiliary devices. Withthe cut-out 864 to thereby identify a full engagement of the ports.Additionally, some resistance is also provided between the ports to helpavoid incidental release.

Although the present invention has been illustrated and described withrespect to several preferred embodiments thereof, various changes,omissions and additions to the form and detail thereof, may be madetherein, without departing from the spirit and scope of the invention.

1.-34. (canceled)
 35. A method for advancing a flexible device into aparanasal sinus, the method comprising: (a) inserting a guide catheterinto a head of a patient, wherein the flexible device is eitherpreloaded into the guide catheter or advanced into the guide catheterduring or after insertion of the guide catheter into the head of thepatient; (b) moving a distal end of the guide catheter within the headof the patient; (c) generating a suction force proximally through theguide catheter, around the flexible device, and within the head of thepatient, via a suction source attached to the guide catheter, whereinthe step of generating the suction force is performed while the flexibledevice is disposed within the guide catheter; and (d) advancing theflexible device out of the distal end of the guide catheter into theparanasal sinus.
 36. The method of claim 35, wherein the act of movingthe distal end of the guide catheter within the head of the patientoccurs before advancing the flexible device out of the distal end of theguide catheter into the paranasal sinus.
 37. The method of claim 35,further comprising retracting the flexible device through the distal endof the guide catheter.
 38. The method of claim 37, further comprisinginserting a flexible irrigation catheter through the distal end of theguide catheter and distributing irrigation fluid into the paranasalsinus of the patient via the flexible irrigation catheter.
 39. Themethod of claim 38, further comprising generating the suction forcewhile distributing irrigation fluid into the paranasal sinus of thepatient.
 40. The method of claim 35, wherein the distal end of the guidecatheter defines a curved profile.
 41. The method of claim 35, whereinthe guide catheter comprises a shaft extending into the distal end,wherein the distal end is more flexible than the rest of the guidecatheter.
 42. The method of claim 35, wherein a hub is connected to aproximal end of the guide catheter.
 43. The method of claim 42, whereinthe hub is formed from two pieces.
 44. The method of claim 42, wherein avalve is housed within the two pieces of the hub.
 45. The method ofclaim 35, wherein the flexible device comprises a guidewire.
 46. Themethod of claim 35, wherein the flexible device comprises a ballooncatheter, wherein the method further comprises inflating the ballooncatheter.
 47. The method of claim 35, further comprising creating anartificial opening into the paranal sinus, wherein the flexible deviceis inserted through the artificial opening.
 48. The method of claim 35,further comprising suctioning debris from the head of the patient.
 49. Amethod for advancing a flexible device into a paranasal sinus, themethod comprising: (a) inserting a distal end of a guide catheter into ahead of a patient, wherein the flexible device is either preloaded intothe guide catheter or advanced into the guide catheter via an instrumentport during or after insertion of the guide catheter into the head ofthe patient; (b) moving the distal end of the guide catheter within thehead of the patient to position the distal end of the guide catheteradjacent to the paranasal sinus; (c) generating a suction forceproximally through the guide catheter, around the flexible device, andwithin the head of the patient via a suction source coupled to a suctionport; and (d) advancing the flexible device out of the distal end of theguide catheter within the paranasal sinus while the step of generatingthe suction force is being performed.
 50. The method of claim 49,further comprising generating the suction force after advancing theflexible device out of the distal end of the guide catheter within theparanasal sinus.
 51. The method of claim 49, wherein a seal is placedbetween the instrument port and the suction port.
 52. The method ofclaim 49, further comprising irrigating the paranasal sinus afteradvancing the flexible device out of the distal end of the guidecatheter.
 53. The method of claim 49, wherein the flexible devicecomprises a balloon catheter, wherein advancing the flexible device outof the distal end of the guide catheter within the paranasal sinusfurther comprises inflating the balloon catheter is dilate an ostium.54. A method for advancing a flexible device into a paranasal sinus, themethod comprising: (a) inserting a guide catheter into a head of apatient, wherein the flexible device is either preloaded into the guidecatheter or advanced into the guide catheter during or after insertionof the guide catheter into the head of the patient; (b) advancing adistal end of the guide catheter within the head of the patient andfurther positioning the distal end of the guide catheter adjacent to theparanasal sinus; (c) generating a suction force proximally through theguide catheter, around the flexible device, and within the head of thepatient, via a suction source attached to the guide catheter, whereinthe step of generating the suction force is performed while the distalend of the guide catheter is being advanced or positioned within thehead of the patient; and (d) advancing the flexible device out of thedistal end of the guide catheter into the paranasal sinus.